![Narelle Nancarrow says farmers need to watch out for crop viruses this year. Photo by Gregor Heard. Narelle Nancarrow says farmers need to watch out for crop viruses this year. Photo by Gregor Heard.](/images/transform/v1/crop/frm/5Q2j7ezUfQBfUJsaqK3gfB/ad2f5187-1544-4cde-abd8-0a83382e6af3.JPG/r1747_307_6000_4000_w1200_h678_fmax.jpg)
Australian farmers will have to be on high alert to control the green bridge of volunteer cereals and weeds that could allow the spread of damaging crop viruses into the upcoming crop.
Subscribe now for unlimited access to all our agricultural news
across the nation
or signup to continue reading
PhD student Narelle Nancarrow, of the University of Melbourne, said farmers had to be proactive to control the impact of cereal viruses such as the range of yellow dwarf viruses (YDVs).
"Once the crop is infected by a YDV there is little that can be done in terms of treatments, so that means the prevention is critical," Ms Nancarrow said.
She said that monitoring of grass weeds and volunteers that have emerged after solid summer rain should be undertaken regularly to look out for aphids, one of the major vectors for plant viruses.
"The best plan is to control volunteers and grass weeds and keep aphid numbers down," she said at the recent Grains Research and Development Corporation (GRDC) update in Bendigo.
Agronomists at the event noted that aphid numbers had begun to build up in recent weeks with ample green pick in the paddocks.
Ms Nancarrow said crop viruses were most likely to cause yield penalties in early growth stages when the crop is at its most susceptible.
Worryingly she said new YDV species have been found in Australia recently.
This will mean a shake-up of resistance genetics, with varieties needing to also be assessed for the new strain of the virus.